there were more than 100 MB of updates!How can I set this Settings>Details>Check for Updates' to really show me if there are updates?Or even better, how can I install a GUI that warns automatically if there are new updates?

Unfortunately, I am not very well versed in Debian, and a lot fo Googleing did not help either.

Now heretical: why can only root get essential security updates in a multi-user Debian system?

We have a multi-boot and multi-user system. Debian 9 is our main thing; we use Windows 10 only extremely rarely. But Windows has the advantage that every user can get essential security updates without exerting admin rights. Why is this not possible in Debian - or Linux for that matter? What is the point to prevent this?

debcub wrote: . . . Windows has the advantage that every user can get essential security updates without exerting admin rights.

That's exactly why Windows has such a notorious security problem. The Unix system of two distinct levels of permissions (which Linux uses) serves to keep unauthorized users out of those areas that could be vulnerable. Learn to love this; it will protect your system if properly preserved.

What would be wrong if the system could do essential security updates? Without interference from the the user? What would be wrong if my wife could use Debian without waiting for me to come back home and do "# apt upgrade"?

debcub wrote:What would be wrong if the system could do essential security updates? Without interference from the the user? What would be wrong if my wife could use Debian without waiting for me to come back home and do "# apt upgrade"?

There's nothing wrong with it if that's what you want, they told you that you can set it up that way. It's called unattended upgrades.

If you don't know how to do something, that doesn't mean it's impossible. After you have read the documentation, then ask questions. There's no point in asking other people to read the wiki page for you and explain it.

..or arrguing about whether it is a good idea or not.

Something to get your mind around, is debian has dozens if not hundreds of setups. It's not like ubuntu. Nobody knows what you installed, because all you said is "debian" and not everyone has a software>menu>gui thing like you describe in your problem. If you get specific and explain what tool you are using on what desktop environment, then you will probably get more specific help.

bw123 wrote:Nobody knows what you installed, because all you said is "debian" and not everyone has a software>menu>gui thing like you describe in your problem. If you get specific and explain what tool you are using on what desktop environment, then you will probably get more specific help.

Like I said in my first post "Debian 9 Stretch Stable". I confess I forgot to add "Gnome Classic". I did not know that there are so many different varieties of Stretch, are they? Sorry!

This is the GUI that puzzles me. It says "Download and install automatically", updates that is. But it does not to my experience. I cannot add the screenshot because I get "Sorry, the board attachment quota has been reached.". But you can find it if you type "update" in the search field of the Activities Overview and select then "Software & Ubdates".

You could do some searches on it by that name, gnome-packagekit, or check some help if gnome has a help app. Also, searching bug reports is often really helpful.https://bugs.debian.org/gnome-packagekit

If there are debian-specific changes to the package, they would be described in /usr/share/doc/gnome-packagekit on your system. That folder also may have other information about the package. Also check the unattended-upgrades folder in /usr/share/doc It may be that the feature is disabled by default, I don't know. Some people consider this kind of thing security-related, and debian has been known to disable known security risks by default in packages. I do agree with that, and would not like this enabled by default.

debcub wrote:... I did not know that there are so many different varieties of Stretch, are they?...

Some people use Gnome, long considered the Debian default. Some people use KDE, some use Xfce, some Cinnamon, some Mate and the list goes on and on and sometimes things are done differently in different environments. That's why you need to tell what you are using so that someone with knowledge appropriate for your environment can give you a useful answer, sometimes things work the same across environments but not always.

Help: to get my point through I need to attach two small jPG screenshot picture files (33.1 and 38.7 kB). However, since some time I always get "Sorry, the board attachment quota has been reached." when I try to upload. There were never problems before that.

You upload the image to a storage site, and then using the img tags , and the url tags, copy paste a link to the image, in the img tags, preferably a small image or thumbnail , the url tags are the link to the full size image.